The present invention relates to a stapler powered by a motor and the punching member is connected by two arms which are moved by a cam device so that the lowering action of the punching member is evenly and in stable.
A conventional power stapler 70 is shown in FIGS. 6 and 7 and generally includes a punching member 76 which is pivotally connected to an inside of an arm of the stapler 70 and staples are received in the punching member 76. A motor 71 is connected in the power stapler 70 and is connected to a gear system 72. A pinion T7 driven by the motor 71 is connected to a gear T8 and a gear disk T10 is co-axially connected to the gear T8 and drives gear T9. A gear disk T11 is co-axially connected to the gear T9 and drives a gear disk T12. A shaft 73 extends from a side of the gear T12 and a cam shaft 74 is connected to the shaft 73. A cam 75 is connected to the cam shaft 74 and is retained in a semi-circular frame 77 and when the cam 75 is at its high position, the punching member 76 is positioned at not-in-use position. When documents are inserted into the space below the punching member 76, the cam 75 is moved to its lowest position by the gear system 72 to press the punching member 76 downward and penetrate a staple through the documents. However, the cam 75 contacts a side on the top of the punching member 76 so that the punching member 76 is applied an eccentric force which tends to tort the punching member 76 and the force of the two ends of the staple are not evenly. Because the cam shaft 74 is cantilevered so that it is worn out and/or deformed after being used for a long period of time. The contact between the cam 75 and the punching member 76 is an impact type that accelerates the deformation of the cam shaft 74.
The present invention intends to provide a power stapler wherein the punching member is connected between two arms and two cam devices are connected on two distal ends of the two arms so that the punching member can be smoothly lowered and raised.
In accordance with one aspect of the present invention, there is provided a power stapler and includes a base and a punching arm is pivotally connected to said base in which a gear system and a motor powering the gear system are received. A punching member has an end pivotally connected to said base and a punching plate extends from the other end of said punching member. A shaft extends through said punching member and two arms each have a first end thereof connected to two ends of said shaft. Two cam devices are respectively connected to two respective second ends of said two arms. The two cam devices are connected to an axle of one gear of said gear system so that when the gear is rotated, the cam devices moves the two arms.
The primary object of the present invention is to provide a power stapler wherein the punching member is connected between two arms which have two respective cam devices connected with the gear system so that the punching member can be pivoted smoothly and in stable.